For this size Blast nozzle here is the size and the air required for best performance

NO.350 Nozzle bore – 3/16″/4.8mm
Length- 140mm
Thread Size: 50mm
Inlet Size: 25mm
Air requirement- 45/80CFM or
Horsepower – hp/(kW) – 10.5/(7.83)

THE AIR REQUIREMENT IS TO ACHIEVE 100 psi AT THE NOZZLE